There is a company that offers an adapter for that swap, I believe it is JPT out of Michigan. The AOD is not up to the torque in stock form, it will need a performance rebuild and a good cooler. Also, there are certain year AOD's that can work and others that absolutely won't, the guys at JPT can fill in the blanks. It won't be cheap but the results are impressive from the reports in Mustang and Ford Magazine's review of the swap about 6 months ago.
I wouldn't recommend it unless you spend some HUGE bucks on a VERY STRONG aftermarket one. I have several friends who have bought "performance" ones and tried them in Mustang GT's behind small blocks and they definately dont last very long...
The one guy had a 347 stroker with a Vortech and Nitrous and it lasted about 3 months and he wasn't even driving it on the street!
Just my .02
The AOD I built for my own car has been handling 480 ft lbs on a daily basis for almost 3 years. It is behind a 460 with an Art Carr adaptor plate. I am not a big fan of adaptor bells, JPT makes the bell for Lentech and if it is like the 460 to AOD bell it's maximum convertor size is 11". I installed my AOD for fuel efficiancy and didn't want to go with a high stall. If I wanted a trans for racing I would have stayed with the C-6 or gone C-4 if every tenth was important.
One day I may find the time to put together an adaptor plate from FE to small bell to run an AOD. Just too busy lately and no FE to test with.